Annual report . ing a mass of red syenite in Cairo andAlma townships. Xumerous small masses of porphyry occur to the north of David-son creek, and along the Montreal river, north of Matachewan Mines the acid intrusives are massive and fresh in appearance, and again maybe greatly altered and partly schistose. Some of the red porphyry shows distinctphenocrysts of feldspar. Such a rock is seen in the larger masses of orthoclase orsyenite porphyry on the Davidson claims. A narrow dike of this rock intrudes olderporphyry on claim 5376. A granite porphyry exposed in the central pa
Annual report . ing a mass of red syenite in Cairo andAlma townships. Xumerous small masses of porphyry occur to the north of David-son creek, and along the Montreal river, north of Matachewan Mines the acid intrusives are massive and fresh in appearance, and again maybe greatly altered and partly schistose. Some of the red porphyry shows distinctphenocrysts of feldspar. Such a rock is seen in the larger masses of orthoclase orsyenite porphyry on the Davidson claims. A narrow dike of this rock intrudes olderporphyry on claim 5376. A granite porphyry exposed in the central part of claim5406, south of Matachewan gold mines, is greatly altered to schist, and is an older-looking rock than the syenite porphyry. A similar rock occurs on the east and westshores of the south bay of Otisse lake. A fine-grained, red hornblende syenite,quite massive, occurs on the west shore of the Montreal river, one-half mile northof the Matachewan Mines landing. Small outcrops of syenite were also observed. Quartz veiiilets in syenite porphyry, Davidson claim, Matachewan. farther up the river. Back from the river there is a heavy drift, and rock outcropsare infrequent, but outcrops of reddish intrusive rock are occasionally seen in thearea west of the river to Otisse lake. It is probable that the different types of acidintrusives may belong to different periods of intrusion in Algoman times, duringwhich time it is believed that most of the gold deposits of Xorthern Ontario wereformed. Ore DepositsDavidson Claims AVliile tlie presence of gold-bearing veins in the Matachewan area has beenknown for several years, prominent attention was directed to the area by the dis-covery in 1916 of gold on the Davidson claims, in Powell township. During 1917 1920 Matachewan Gold Area 57 these claims were explored by means oi trenches and several shallow cuts throughthe decomposed surface rock, and gold-bearing material found in several places;most work was done on irregular masses of qua
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectminesandmineralresou
